Think of me this Saturday morning, in the early dawn hours, if you will. I'll be somewhere out in the ocean, about 45 miles south of Key West, beginning a 24-hour continual swim through the Gulf Stream, back toward the Florida coast. This is a full dress rehearsal for the Cuba-to-Florida swim I'll be attempting later in the summer...

FROM THIS EPISODE

This is Diana Nyad for KCRW, and this is The Score.

Think of me this Saturday morning, in the early dawn hours, if you will. I'll be somewhere out in the ocean, about 45 miles South of Key West, beginning a 24-hour continual swim through the Gulf Stream, back toward the Florida coast. This is a full dress rehearsal for the Cuba-to-Florida swim I'll be attempting later in the summer.

On one hand, 24 hours should seem within reason for me at this point. Since January, I have been training every other week in either Cancun or St Maarten. Eight-, ten-, twelve-, and 15-hour swims, each time out feeling stronger, in better shape, mentally tougher. But, believe me, I'm still humble and admit to being duly nervous about these long 24 hours ahead on Saturday. Twenty-four hours in the sea, never getting out on the boat, never hanging onto the boat, is always, always a daunting endeavor and, even though the actual Cuba Swim will take perhaps as many as 60 continuous hours, I respect the fact that this swim this weekend is going to demand all the best within me.

And it's not just me. These long swims are analogous to mountain climbing. They're expeditions. When I say “full dress rehearsal” I'm referring to an Operations Team of 24 people, all experts in their fields. World-class navigator, competitive ocean kayakers who will carry the Shark Shield electric devices and control their boats very close to me, the preeminent expert on the movement of the Gulf Stream, my personal handlers who act sort of like corner men during a boxing match, knowing when to push me, when to coddle me if the elements act up or if I'm having any kind of physical or psychological troubles. There's a meteorologist, a medical doctor, boat handlers, safety divers in addition to the kayak paddlers.

As I say, it's an expedition. This last training swim is in part for me, to give my shoulders one last rigorous push, get my mind set grooved into a tunnel focus, so that no matter what comes our way on the Cuba voyage, I'll hopefully be able to overcome it. But these 24 hours are all about the TEAM as well. We need to establish smooth communications, between me and the handlers on the escort boat, between the navigator and the off-shore Gulf Stream expert, between the two sets of crew…the captain of the three boats has his crew and the navigator has his crew….between the escort boat and the two sets of shark teams…the kayakers with the electronic devices and the safety divers who will actually enter the water if sharks are following and displaying aggressive behavior. We need to go through the entire night and be visible to each other without casting bright lights onto the surface, which attracts sharks.

This is a lifelong dream of mine, swimming the 103 miles from Cuba to Florida. Back in my youth, in 1978, I tried like heck to make it across. Forty-one hours, 49 minutes later, a raging sea kept me from the Florida shore.

This time, at the age of 60, I hope when I do walk out onto that shore that a clear message will emanate: that the millions of baby boomers my age are still strong and vital….that our best days are most definitely NOT all behind us.

My colleagues at KCRW have been wonderful, supportive teammates to me in this quest. If you're interested, you can follow the expedition throughout the 24 hours this weekend and the Cuba Swim throughout the summer at KCRW.com. CNN will be covering both swims live as well.